US2731503A - Alcohol synthesis process - Google Patents

Description

W. J. MATTOX ALCOHOL SYNTHESIS PROCESS Filed May l0, 1951 Jan. 17, 1956 `yield of aldehyde andalcohol.

United States Patent' f 2,731,503 i ALCOHOL SYNTHESIS 'rnocnss Application May 10, 1951, Serial No. 225,548

6 Claims. (Cl.` Zoll-638) i The present invention relates to an improved synthesis process for the production fof alcohols by reacting organic compounds having olefinic linkages with gas mixtures containing CO and H2 at high pressures and elewatediternperatures` in the presence of suitable catalysts. Moreparticularly, `the invention is concerned with an improved process `for producing alcohols from oleuic` feed stocks which normally undergo the carbonylation reaction with difficulty.

The` invention further relates to the lpreparation of narrow boiling alcohols of high quality suitable for use as intermediates for plasticizers from wide cut olefin frac, tions.` Still more `specifically the inventionl relates to the production of `octyl alcohols which` are particularlyisuitable as intermediates in the manufacture` of plasticizers, `from cheap and available raw materialiI The synthesis ofoxygenated organic compounds from olefinic compounds` and mixtures of CO` antilla` is `now well known in the art. The `olefinic starting material is lreacted `in the liquid state with CO `andHz in the pres* ence` of a group VIII metal catalyst, usually cobalt. The primarynreaction product consists essentially of organic carbonyl compounds, mainlyaldehydesyhaving one more carbon atom per molecule than theolenic feed material. The `oxygenated product may` then be hydrogenated in a second catalytic ,stage to convert the aldehydes to the corresponding alcohols. f

i `Suggested as starting materials, have been practically "all types of organiccompounds `having an olefinic double bond, including aliphatic olefns and diolens, cyclob lens, aromatics with `olefinic side chains, oxygenated organic compounds with olefinic `double bonds, and `the like. `The metal may be present as` a solid or in the form of a compound soluble in the olefinic feed stock.` LSuit`` able reaction conditions include temperatures'of about l5.0".450 F., pressures of l00-300 and `higher atmospheres, Hz to CO ratios of about 0.5-2z1, liquid feed ratesxofabout `O.'lwto 5.0 v./v./hr. and gas feed rates o f about 10m-,45,000` standard cubic `feet of gas mx ture per barrel of liquid olefin feed.

Similar or higher temperatures and` pressures, and hydrogenation catalysts such as nickel, copper, tungsten, oxides or sulfides of group VI and group VIII metals, etc. may be employed in the second stage for hydrogenation of the carbonyl compounds to alcohols.

It has, however, been found that certain olefins are considerably less adaptable to the alcohol synthesis' process than others, and that, for a given olefin, one isomer `may give an aldehyde and anwalcohol yield of over 90%, another isomer of the same olefin may give a negligible These d iercnces may Ibe attributed to 1steric effects. Thus' straight chain alpha olefins are usually found to give thehighest yield of reaction products, whereas triand tetra-substituted olefins are highly resistant to reaction, and limit the conversion obtained in thesynthesis reaction. 'clfhisprolzv` lem "becomes particularlyacute when `the olefinic feed is not a pure compound but a mixture of isomers boil- 2,73i,5l3 Patented Jan. 17,` 1956 ing within a relatively narrow range and consisting of isomeric olefins of the same molecular weight. This is, of course, true in most commercial operations wherein it is not feesible to isolate pure compounds.

For instance, in the process of manufacturing octyl alcohols from heptene on a commercial scale, an abundant source of heptene is available from the controlled polymerization, in the presence of `a phosphoric acid catalyst, .0f a mixture of butylenes' and propylene, available in practically unlimited supply `in petroleum refineries. The polymer is distilled and theheptene fraction is` isolated. As would be expected, the product is a mixture of isomeric heptenes.` It is convenient to classify olefnic types in the following manner, depending upon ing in the range of about 168 to 210 F., shows an olefin typefdistribution as follows:

Type: Weight, per cent I l II 12 111;.- 12 VIV s `55 V L-.i 20

It is thus` seen that a `preponderant fraction of the heptenes is present as tertiary olefins. Now though tertiaryolefinsof type III are quite reactive in the carbonylation reacti0n,others, particularly those represented by group V, react Very `slowly or not at all. 'For `example, 2,3-di-methyl pentene-Z reacts `with CO and H2 to form aldehydes at a substantially slower rate than it reacts with H2 alone to form the saturated paraffin. The presence, particularly `of the type V typeof olefin inthe feed to the primary carbonylation reactor puts a large burden on the final `distillation section and cuts down materially the plant capacity, for either the olefins are recovered unchangedor as paraflins, both of which are `undesired ina process where the primary purpose is toisynthesize aldehydes and alcohols, giving as a final result, low` overall lconversions of olefin. c

lt is, therefore, the principal purpose of the present invention to utilize more completely the olefin content of a feed tothe alcohol synthesis process and to obtain high olefin conversions.

Itis also a purpose of the present invention to prepare afeed for the carbonylation reaction containing substantially less type V (tetrasubstituted) olefins from A further purpose Yof the present invention is to prepare a superior alcohol rmore suitable for employment as intermediate in the manufacture of plasticizers and detergents. Y 4 Other purposes and advantages of the invention will become apparent hereinafter.

The present invention overcomes ythe difiiculti'es arising from the use of feeds containing olefinic types IV and V and affords various additional advantages. `These, advantages,v the nature of the invention, and the manner in which it is carried out will be fully vunderstood from the followingdescription thereof read with reference to the accompanying drawing which shows a semi-diagrammatic view of apparatus adapted Vto carry out the invention. Primary octyl alcohols are of great economic importance andint'erest because of their use as intermediates in the manufacture of plasticizers such as thoseof vthe di-ester type. For this purpose these alcohols may beesterified phorc, aconitic, and other diand polybasic acids to yield esters suitable as plasticizers for vinyl resin cellulose acetate,.cellulose ethers, cellulose nitrate and also, for synthetic rubbers such as Buna S and the acrylonitrile-dioplefn polymers. Plasticizers are-usedin the compoundingof these resinous and rubber materials in order to increase flexibility' resistance to brittleness at low temperature and resiliency. VHitherto, these alcohols have been supplied on a commercial Vscale mainly by such comparatively costly procedures as aldol condensation of butyraldehydes, followed by( dehydration, and hydrogenation of the unsaturated octyl aldehyde." It is a'purpose' of vthe'preserit invention to disclose a'novel and economically attractive `:tation process are rderived not only from butylene-propylenecopolymerization, but also, from demethylation or disproportionation reactions of higher molecular weight materials such as Ca and Cs polymers. Suchvdisproportionation or demethylation reactions have a certain similarity to cracking and hence, as might be expected, occur with greater frequency as the temperature of the polymerization is increased. There are thus two ways of increasing the yield of C7 olefins in a given polymer plant. These are: (l) increasing the butylene/propylene ratio in the polymer plant feed, and (2) operating at as high a temperature as possible. However, even under the best conditions,the yields of C7 olefins are fairly small compared to other constituents of the total polymer product, and under cer- Y with suitable acids such as phthalic, adipic, sebacic, phostain conditions, .become limiting in supply when considering large scale alcohol production by the carbonylation or aldhyde synthesis reaction. It is obviously highly desirable to increase the C1 olefin content of the polymeric product to provide cheap sources of'this raw material for octyl alcohol production. As indicated aboye, heptenes from a polymer plant source are convertedV to octyl al-, cohols by the carbonylation process and the alcohols esterified to produce plasticizers. The best plasticizer is,

' generally speaking, the one which bestows a given degree is more expensive than the resinous or rubber material in process for manufacturing octyl alcohols which are particularly suitable for the manufacture of plasticizers of the alcohols from various C7 fractions commercially available,

i.V e., that are produced on a scale large enough to provide aY steady and available source, of feed for the processing fof alcohols on a commercial scale to supply a maket of from 3,0 to 100 million pounds or more of alcohol a year. The olefin fractions readilyavailable are principally those derivedand resulting from the processing of petroleum distillates. Thus, available on a large scale are olefnfractions from thermal and catalytic cracking processes, either directly or from polymerization of olefns from these cracking processes. These sources all produce in large supply, olefin Vfractions containing substantial amounts of heptenes. f

One ofthe most-promising sources of supplyof heptenes is the olefin polymerization process -wherein lowmole'c'ular weight olens, such as propylene and butylenes, are polymerized in the presence of a catalyst, such as phosphoric acidon a siliceous carrier, to produce a large variety o f olenic products, boiling in the gasoline range and above. Many refinery light end streams contain appreciable amounts of olefins, and these may readily be converted into polymeric olefns which have considerably greater value as high octane gasoline.

Normally, light ends polymerization plants are operated l in refineries to convert a wide variety of lower olefinic materials topolymers suitable for use in gasoline. Ordinary practice is to include propylene, the butylenes and in certain cases, the amylenes, into polymer plant'feed stocks.l The portion of the resulting polymeric materials boiling' inthe C7 range is dependent upon the composition ofthe olefinic feed stock as well as upon the operating variables of the polymerization process, such as temperature, pres@ sure, contact time and the number of stages in the operation. In general, the amount of C7 fraction in the total polymer increases with increase in butylenes inthe feed stock and also, with increase in the temperature of'operation. It is pictured that C7 hydrocarbons in the "poly'rrleri-v which it-is incorporated. It is obviously desirable, therefore, to produceby the carbonylation reaction from polymer plant olefins, an alcohol which, on esterification with sucha'cids as phthalic, adipic, sebacic, phosphoric, etc.,

" yields esters of the highest possible efficiencies.`

yInV accordance with the present invention, the overall yield of h'eptenes for conversion into iso-octyl alcohols, and the resulting alcohol itself, is considerably improved by employing as a feed to the carbonylation reaction the mixed hexene-heptene product resulting from the polymerization of propylene or from the copolymerization of propylene and butylene in the presence of a phosphoric acid-kieselguhr catalyst. As has been pointed out, the heptene fraction ofthis polymerization product is rela` tively small; the hexene fraction is also relatively small TABLElr-POLYMERIVZATION OF PROPYLEN Effect of butylenes in feed on product distribution [400 F., 1000 p. s. i. gl., 0.33 gaL/hrllheed rate, 40 mol. percent olens in ee Y Volume percent Olen Cut on Total Polymer telggkxfge'g N-Butene Iso-Butene Mixed Butenes\ Y 1 Os C1 C5 O1 i Cn A C1 n zo 5.5 7.o 5.5 7.o 5. 6. 5 8. 3 (i. 5 12. 0 6. 5 9. (i. 3 10. 7 6. 0 17. 0- 6. 3 13. 6. 0 13. 0 5. 8 22. 0 6. 0 16. 5. 5 15.0 5. 5 26. 5 5. 7 19. 4. 7 19. 5 4. 6 38. 0 5. 0 27. 4. 0 18. 5 Y 4. 0 38. 0 4. 3 28.`

In Vaccordance with the invention, themixed polymer convertedto thjecorresponding alcohol mixture coumodulus).

sysneoa sstingof iso-.heptyl and iso-octylalcoho'ls, which lmixture is readily separated by simple distillation. rThe recovered heptylwalcohol is then dehydrated `to the corresponding heptene, which is `then inturn reacted with CO and Hz and a cobalt catalyst to form aldehydes and then alcohols.` By this process, not only is the available feed stockfor iso-oetylialcohol considerably increased, but the `quality of the final product` is considerably improved. During the first carbonylation reaction` of the mixed feed, the type `IV andtype V oleiins referred to previously, i. e. those containing a high degree `of branching,` pass through the aldehyde synthesis reaction virtually unreacted and are separated, usually in theirhydrogenatedrform, in the predistillation stage, priorto the separation of the` C'z and `Ci; alcohols. The heptene fraction resulting from the dehydrationof the Cv alcohol, however, is, because of its method of preparation, practically free `of type IV and type V olens. As a result, this feed may be treated under considerably more favorable conditions to produce a higher yield of better product than `would otherwise be obtainable from a similar` amount of C7 olefinobtained in the normal polymerization process. Thus, advantages` in product quality would include greater plasticizer, effi ciencies and improved stress-strain properties (lower Also, among operative advantages are irnproved `conversion per pass and increased throughput in y the carbonylation reactor,coupled` with increased ear-` "bonylation eiciencies due to the, greater proportion of oletins oftypcs I-III in the reactor. t a

The present invention is of particular advantage in an operation wherein the heptene fractionutilizable forcenversion into, octyl alcohol is of high quality andcontains olenic` constituents particularly adapted to conversion to .plasticizing alcohols, but the yield of` this fraction is low, Thus, it hasbeen found that `the plasticizer efl"1` ciencies of esters derived from octyl alcoholsproduced from polymeric C7 `oletins .(i` e. heptenesderived from polymerization oflow` molecular weight` olens of a phosphoric acid catalyst) are not` uniform, butdepend to a lanarlced extent upon the nature of the olefinswemployed as, feed to` the polymerplant. That is` `for a given temf peraturc range the `heptene fraction when` converted into octyl `alcohols and then into esters, is `foundtto hai/edifferent `plasticizer eiiiciencies dependentgupon the nature of the lolens `employed ,asfeed to the polymer unit. Furthermore, it has been foundthat the` magnitude of the eifect of the feed stoclfiycomposition varies with `the `temperature of the polymerization. More specifically, it has been found thatfalcohol `products giving esters of superior' plasticizer eiciencies are prepared by excluding isobutylene substantially completely from the feed to, the polymer plant."` Alcohols and estersof` highest efficiencies were obtained by using exclusively, propylene vor. propylene ethylene mixtures and excluding by suitable reinoval,` all butylenes and `higher hydrocarbons from the feed. It

was found that though substantially pure propylene or propyleh'e-ethylene mixtures make the mostfsuitable feed in terms of alcohol` and esterplasticizing properties, `the addition of some butylene was required in `order Ato maiutain` polymer yields; `the total `exclusion of butylenes was accompanied byrelatively low yields of `@infraction and itwas also found that inclusion of isobutylene to `this feedwto the polymerrplaut increased substantiall-y-the yjse cosities and cold temperature `brittlenesscharacteristics oflthe octyl alcohols and esters. t i t `To summarize, therefore,` the C7 olefin product vof highest quality in` terms of` suitability `ofthe resulting octyl` `alcohol for plasticizing'purposes isuprepared` by` polymerizing `fnopyleue in the substantial* absence of butylenes. :Theyields of C7 fraction are, however, quite "Q Somewhat higher yields are obtained 'by A"including normal `butylenes, though-the product is not quiteas good;

y Even "higher yields are realizedWhen""isobhtylene is ina f a eluded in the feed, but in this case the product contains a large amount of type 1V and type V olefins, and the octyl alcohol quality is inferior.` These results areshown in Tables Hand III. y y

However, by including the hexene fraction from the polymerization process, particularly in the `operation wherein butylenes are excluded, and operating in accordance with the invention, a considerably larger feed stock is available for the production of high quality octyl alcohol. Thus,4 the Ce olefin fraction from a propylene polymerization process` over phosphoric acid-diatotnaceous earth catalyst amounts to about '7 vol.` per cent of the total polymerizate, whereas the C7 fraction amounts only to about 5.5%.

Having set forth its general nature, the invention will best be understoodfrom the following more detailed description in which reference will be lmade to the accompanying drawing. The description vthat follows` `is an embodiment wherein propylene and n-butylenes are poly merized and theC and C7 olen fractions are separated from `the polymerizate `and employed as feed to the alcohol v.synthesis process.` It is `to be understood that the invention is not to be restricted to the employment of this particular feed or to these two components; any mixture of olefins consisting of two olens differing by one carbon atom may be employed. y

Referring now to the figure, the total polymerizate yfrom aA PzOs-diatomaceous earth polymerization unit, wherein a mixture of C3 and C4, preferably normal C4, oleiins are polymerized to form a liquid product ispassed to distillation zone 2. Light material is taken `overhead through line 4. The heart cut, corresponding to `thecomf bined hexene and heptene fraction, is withdrawn through line 6. This is the fraction boiling between abouty 113 and` 215 F. at atmospheric pressures, and may have a heptene` content of about 13 vol. percent and a hexene content of about 6.5 vol. percenn The olefin is passed to` mixer 8 wherein cobalt oleate or othersuitable cata: lyst is added through line 1l)` in such proportions that the weight of cobalt Ain solution is about O15- 0.3% of the `totalliquid. a l y The mixture isthen pumped to preheater 12 wherein itis brought to the` desired temperature range and then discharged via `line` 14 to the bottom of primary `carbonylation reactor 16. Reactor 16 comprises `a high presure reactor vessel which may', if desired, be packed with non-catalytic material such `as ceramic rings, porcelain or quartz chips, pumice andthe like. It may also be divided into discrete packed zones separated by any suitable means, such as `support grids, etc. or lit may comprise but a single packed zone, or it may contain no packing` A stream of `synthesis gas comprising H2 and CO in the approximate ratio of 0.5-2 volumes H2/,CO, 'preferably 1.0-1.2 to 1,`is fedinto. reactor lrthrough `line 18. The synthesis `gas stream is a` composite of fresh gas and recycle,` and .liio'ws upwardly `with the `olefin feed through reactor 16. .The latter iis preferably `operated atta `pressure of `about Z500-$500.11. s. ;i. gend at a ,carefully controlled temperature range: of 300%3605 F., preferably between 340-360 F; The rate of-ow of synthesis gases and `of olen through `reactor'l is so regulated `that the desired conversion level of olefin is obtained. These conditions include an olefin fresh feed rate of about 0.44.0 v./v./hr., fresh synthesis -gas feed rates 'of 1000-10,`000 cu. ft./barrel of olefin, and a nominal residence time of about 1-3 hours.

The carbonylation reaction `may be carried Outsub stantially adiabatically, that is,i no external cooling means such 'as tubes or coils `need be provided, but cooling and temperature control of the" highly exothermic reaction isncarried out b y recycle of a portionof 'the prod nel, as dessribfd below Liquidoxyg'enated reaction products containing catalyst in solution, as wellajerunreacted synthesis gases are withdrawn Vfrom `an upper portion of high pressure reactor 16 and transferred through line`18 and cooler 20 to high pressure separator 22 where unreacte'd gases are withdrawn overhead `through line 24, scrubbed in scrubber 26 of entrained liquid, Vand preferably recycled to reactor 16 via Vlines 28,and'.18.Aportion of the recycle may be purged through line 30 to maintain thedesired Hz/CO ratio in the feed. Y A

Liquid carbonylation product containing dissolved thereiny relatively high concentrations of cobalt carbonyl is withdrawn from separator 22 via line 32. A portion of this'stream may be recycled to reactor 16 via line 34 to`aid'in the cooling and maintenance of temperature control of theprimary carbonylation stage. Preferably Vrecycle liquid product is injected at various levels within reactor 16 tofobtain close temperature control throughout the whole reactor. Approximately 490-500 volume percent of' liquid reaction product on the fresh olefin feed may be ,recycled for this purpose. "Ihre, temperature of such Vrecycled material is generally dependent on that of the atmosphere, and may be about 30-l00 F. n The balance of the primary reaction product not rccycled torreactor 16, which may comprise, beside dei sired heptyl and octyl aldehydes, also unreacted olefns of the highly branched type, secondary reaction products,Y and dissolved cobalt carbonyls, is withdrawn through pressure release valve 36 and line 38 and passed to decobalting zoneY 40. Within decobalter 40, soluble cobalt carbonyl is removed from the aldehyde product prior` to high pressure hydrogenation in order to prevent itsjdecornposition in the subsequent hydrogenationrstage with consequent fouling of coils and reactor plugging. The'decornposition of the cobalt carbonyl isl obtained by heating the aldehyde product by such means as steam coils, etc. to about 200400 F. at a pressure justhigh enough to keep the components in the liquid phase. Pressures in the neighborhood of 100-150 p. s. i; g. are preferred. The product containing catalystyin solution is injected into decobalter 40 through line 38 and stripping gas such as Ha or steam may be added through line '42 to aid in decreasing the CO partial pressure and decomposing lthe cobalt carbonyl. If. desired, it may be l.advantageous to operatevwith twoor more decobalters, switching the stream from one tov the other as ytheone in" service accumulates excessive quantities lof cobalt metal. The gas streamvcornprising stripping gas and CO may be removed overhead from40 through Yline 44 and used as desired. Y v

VThe liquid aldehyde product no'w substantially free of dissolved' catalyst is withdrawn from 40 through line 46 and passed through filter 48 for removal of any sus-A pended cobalt. The filtered solution is withdrawn: from 48 and rpassed through preheater 50Y tothe bottom portion of hydrogenation reactor 54 via line 52. Simultaneously hydrogen is'supplied to 54 through line 56 in proportions suicient to convert the aldehydic product vinto the respective alcohols.- Hydrogenator 54 may contain aV mass of any conventional hydrogenation catalyst, such as nickel, copper chromite, sulfactive catalyst such asftungsten, nickel or molybdenumsulfide, preferably supported onV lcarriers such as pumice, charcoal, etc. Reactor. ispreferably operated at temperatures of about 400-500 F. Vandpressures of about 2500-3500 asus. f

' The products from thehydrogenation reactor and unreacted hydrogen may be withdrawn overhead through line 58, passed throughA cooler and Vhigh pressure separator 62, whence H2 is removed overhead through 64"for recycleJfThe liquid product is withdrawn from separator 62 through line 66 and, after passing through conventional lowpressure separators and stabilizers (not shown), is Vpassed to hydrocarbon still v68, wherein are distilledV overhead lowboilingfproducts, mostly hydrocarbons boiling below 220 -F. These materials are removed through'70 asfa heads cut and may be used as gasoline blending agents. 'They bottoms from this primary distillation are withdrawn from hydrocarbon still 68 via linel 72 and sent to alcohol still 74 where a 'combin'ed heptyl and octyl alcohol cut boiling withinl the range of270 to .380.e F. at atmospheric pressure is taken. Y

The combined alcohol stream is' then passed through overhead line 76 to. fractionating columnV 78; distillation bottoms boiling above octyl alcohol may be withdrawn through line 77 and be used in any desiredv manner,r as cracking stock, fuel, etc., or they may be'further processed and distilled at subatmosphericpressures to recover valuable oxygenated organic products.

Fractionating column 78 lis operated at carefully controlled conditions to effect a 'sharptseparation between heptyl and `octyl alcohols. Conditions within 78 include temperatures of `345 to 360@ F. The octylalcohol frac# ltion is withdrawn downwardly through line 80 and sent to storage tank 82, from whence the product may be sent to an esterication'plant for conversion into a di-octylester,

such as di-octyl phthalate, in a manner known per se(V '4 to dehydration zone S6. A suitable dehydration catalyst is, for example, active alumina; other materials, such as phosphoric acid, thoria, blue tungsten oxide, anhydrous aluminum sulfate, and the like, may also be used.` Dehydration zone 86 is operated under conditions such that polymerization of the olefin is substantially avoided.

The dehydration of,Y the alcohol is carried out in vapor phase in the presence of a fixed bed of catalyst such as an active alumina, preferably a partially dehydrated alumina or one that has not been heated appreciably above the dehydrating temperature of about 500-800 F. Atmos pheric pressure is preferred for the aliphatic alcohols since the reaction is somewhat more selective to the olefin. Feed rates of the order of 1 to 5 volumes or more of alcohol per volume of catalyst per hour are suitable depending upon the exact temperature employed and the conversion desired. Dehydration under these conditions does not result in more highly branched oleiins but may actually decrease branching under certain conditions. Since conversions of alcohol to olefin in excess of about 90 mol. percent may readily be obtained in this operation, it will not ordinarily be necessary toseparate the small remaining amount of alcohol from the olefin returned to reactor 16. Water resulting from the dehydration is removed.

The olefinicV product resulting from the dehydration of the heptyl alcohols, and consisting primarily of olens of types I, II, and III, is withdrawn from dehydration zone 86 and recycled to aldehyde synthesis reactor 16Vvia lines 88Vand 14 for further conversion into octyl alcohols in a manner already described.

By the process of the present invention, not only is the resulting alcohol of higher quality, but also widerange boiling feeds may beernployed, eliminating costly preparation of feeds specific to the desired alcohol. Also, olefin feeds' that are highly desirable for use as intermediates in the manufacture of plasticizing agents, such as pure polypropylene, but which are present in only small amounts, may now be utilized as a result ofthe application of the present invention, for plasticizer properties become less desirable at polymerization conditions under which the Cv yield in the total polymer increases.

The relationship between yields of polymer and the suitability thereof as rfeed to the alcohol synthesis processv for conversion into plasticizing alcohols, is clearly shown in the tables below. In lTable II are shown the yyields of C7 olefin, the viscosities of the corresponding octyl alcohols, and the plasticizing eciencies of the di'- octyl phthalates when the polymerization unit is operated atrelatively high temperatures of 450500 F., and Table III shows the results at low temperature (380-425 F.) polymerization conditions. f

TABLnn i `Effect' ofbutene content of polymer plant feed on plasticizer eciency of dioctyl `phthalotes under high temperalure polymerization conditions Feed to Polymer Plant Mol Alcohol Modulus at Vol. Per- Percent Total Olean Viscosity, 59% Elonga- Piglr' cent C1 iu Centisttokes tion ('F.), Temp s F Total lPropylene n-butenes i-butenes 68 F p' s* l' Polymer 100 0 0 12. 1 2, 145.l 451 5. 3 90 i 10 0 l2. 3 2,115 450 10. 5 80 20 0` 12.5 `2, 170 496 18. 5 80 i 20 0 12.6 446 14.0 90 0 10 12. 4 2, 240 450 14. 4 80` 0 20 12.7 2, 350 446 24. 8 98 1 l 12. 6 2, 225 449 61 4 90 6 4 12. 6 2, 110 452 11. 5 37 18 12.8 450 28. 9

In the above tests the vinyl resin compound contained 32.7% (wt.) plasticizer, l Plasticizer concentrations 31.6 wt. percent; when corrected to 32.7%, value of about 2,020

p. s. i. indicated.

TABLE III polymerization conditions Feed to Polymerization, Mol

Percent on Total Olens Alcohol hngls Polymerizac'g' el'l Visc., Cs. 9 tion Temp., 7 68 F. Elonogation o F Total Propylene n-butenes i-butenes (3U F') Polymer 97. 1. 6 0. 8 s 421 6. 5 86. 9 8. 7 4. 4 12. 75 2, 2dr()` 422 10. 5 72. 8 1S. 1 9. 1 426 15. 5 89. 4 10. 6 6. 7 gg. 1g. g g 12. 6 2, 140 405-410 'i 87. 4 8. 4 4. 2 ..7 404 8. 5 45. 0 (08.) 37 (Ca.) 18 13. 4 2, 255 380 90. 0 6. 7 3. 3 12. 9 2, 240 (03..) 400 The determination of the tensile, or stress-strain (modulus) properties of the plasticized vinyl blends were car-` ried out by the standard method of extending dumb-bell shaped specimens at 30 F. and recording the stress value at elongation and break point as well as percent extension at the point of rupture. i

The above tables and results show the following:

1. The lowest modulus, that is, the most desirable stress/ strain properties, were shown by di-isooctyl phthalates obtained from C'z olefns produced by maintaining the feed to the polymerization plant substantially free of butylenes and feeding substantially only propylene. However, the yield of C7 oleiins on the total polymer was low.

2. For a given quantity of butylenes in the feed to the polymer plant, at a given polymerization temperature level, normal butylenes yield phthalic esters of lower modulus than isobutylenes.

3. The lower viscosities of the propylene andthe propylene-n-butylene copolymer-derived alcohols appear to be associated with the superior` stress/strain characteristies of the corresponding esters, and for a given amount of butenes in thefeed, alcohols derived from propyleneisobutylene copolymers have higher viscosities than those derived from propylene-n-butylene copolymers.

4. Plasticizer properties become less desirable at polymerization conditions under which C7 yield in the total polymer increases.

It is thus apparent that by employing as the feed to the alcohol synthesis reaction the polymerzate resulting from `using pure propylene, or propylene admixed with only slight amounts of n-butylenes, and by employing the Ce-C'i olefin fraction rather than the C1 fraction, the ultimate yield of high quality Ca alcohol is considerably raised, and the process made economically feasible.

The following table shows the estimated yields of octyl alcohol, based on the totalpolymerizate, obtained when (l) only the heptene fraction and (2) the mixed hexeneheptene fraction resulting from (a) polymerization of pure` propylene and (b) polymerization of a typical propylene-butylene fraction is employed in the alcohol synthesis reaction. The comparatively large yields of isooctyl alcohol obtainable by operating in accordance with the present invention are evident.

Vols. Iso-Octyl Alcohol/ Vols. Total Polymer Oxonation Feed (a) om. DCCSHHW 4 l Polymer Polymer (1) C1 only 3.6 8.6 (2) Cri-C1 11. 0 15. 2

The embodiment of the invention as illustrated in the drawing and foregoing description admits of modifications readily apparent to those skilled in the art, and are within the scope of the invention. Thus, though in the preheptene produced by the polymerization olf a light gase-I ous hydrocarbon feed comprising at least a major proportion of propylene and substantially free of isobutylene, into a carbonylation zone, treating said hexene-heptene mixture with CO and H2 under elevated temperatures and pressures with a cobalt carbonylation catalyst,

ing said aldehydes to the corresponding alcohols, separating heptyl from octyl alcohols, converting heptyl alcohols,n

to heptenes, said heptenes having olenic unsaturation- ,Y substantially on terminal carbon atoms, passing said heptenes to said earbonylation zone, and recovering increased amounts of high quality octyl alcohols.

2. The process of Vclaim 1 wherein said light gaseous hydrocarbons consist essentially of propylene.

3. The process of claim l wherein said light Agaseous hydrocarbons polymerized to form said hexene and heptene mixture comprise a major proportion of propylene and a minor proportion of normal butylenes. p

4. The process of claim 1 wherein said, earbonylation conditions comprise pressures of about 2000 toy 3500 p. s. i. g.V and temperatures of about 250 to 375 F.

5. An improved process for preparing octyl alcohols from an olefin feed stock containing substantial amounts of unreactive tetra-substituted tertiary olens as well as less highly substituted olelins which comprises segregating the olefin fraction boiling between about 113 and 215 F., passing said fraction to an aldehyde synthesis zone wherein an aldehyde product is formed, hydrogenating said aldehyde Vproduct to form an alcohol product Y boiling in the range of about 270-380 F., separating a heptyl and an octyl alcohol fraction, dehydrating said on terminal carbon atoms, converting said lastnamed olens to an octyl alcohol product, and combining said lirstnamed and said last-named octyl alcohol product.

6. An improved process for preparing octyl alcohols of high quality from anl olen mixture consisting essentially of lhexenes and heptenes, said Vfeed being further characterized 'in that a substantial portion V ofjsaid olefins are tri-substituted and tetra-substituted,which comprises passing said mixture to a earbonylation zone, reacting said mixture with CO, H2 and a cobalt earbonylation v catalyst at elevated temperatures and pressures to form a reaction product comprising substantial amounts of Vheptyl and octyl aldehydes produced from nontetra-sub References Cited the le of this patent v UNITED STATES PATENTS Millendorf et al. Apr. 17, 1951

Claims (1)

1. AN IMPROVED PROCESS FOR PRODUCING OCTYL ALCOHOLS OF HIGH QUALITY IN INCREASED YIELDS WHICH COMPRISES PASS ING AN OLEFIN MIXTURE CONSISTING ESSENTIALLY OF HEXENE AND HEPTENE PRODUCED BY THE POLYMERIZATION OF A LIGHT GASEOUS HYDROCARBON FEED COMPRISING AT LEAST A MAJOR PROPORTION OF PROPYLENE AND SUBSTANTIALLY FREE OF ISOBUTYLENE, INTO A CARBONYLATION ZONE, TREATING SAID HEXENE-HEPTENE MIXTURE WITH CO AND H2 UNDER ELEVATED TEMPERATURES AND PRESSURES WITH A COBALT CARBONYLATION CATALYST, WHEREBY HEPTYL AND OCTYL ALDEHYDES ARE OBTAINED, REDUCING SAID ALDEHYDES TO THE CORRESPONDING ALCOHOLS, SEPARATING HEPTYL FROM OCTYL ALCOHOLS, CONVETING HEPTYL ALCOHOLS TO HEPTENES, SAID HEPTENES HAVING OLEFINIC UNSATURATION

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